Backstage - signing in problem?

Does anyone else have this problem??
I want to make myself a member to get acces to the presale for Brussels tomorrow but it doesnt work. I checked everything and tried with 2 accounts and 2 different cc. I always get this screen in the end :

The transaction resulted in an AVS mismatch. The address provided does not match billing address of cardholder. - Your credit card could not be authorized for this reason. Please correct any information and try again or contact us for further assistance.


HELP!!

I'm having the exact same problem